UI

It is used everywhere you need a remote UI with a lightweight installation. It mainly replaces the Webclient (as the support for the plugin technology is discontinued by the current browser generation), but can also substitute a fat client UI.

When loading a png file in the WinCC OA UI, sometimes one of the following warnings can occur.

WCCOAui (<num>), <TIMESTAMP>, SYS, WARNING, 54, Unexpected state, Qt, libpngwarning: iCCP: 
profile 'ICC Profile': 'CMYK': invalid ICC profile color space
WCCOAui (<num>), <TIMESTAMP> SYS, WARNING, 54, Unexpected state, Qt, libpng warning: iCCP: 
known incorrect sRGB profile

These warnings can occur in WinCC OA since 3.14 when a png file with an RGB profile/ICCP chunk defined as "deprecated" is loaded.

WinCC OAuses version 1.6 of the libpng standard as a third-party component. These warnings have been implemented in this version of libpng.

Basically you can just ignore these warnings, and nothing will happen.

How to identify the relevant pngs

There are several programs for identifying png files, e.g. PNGcrush.

The command line option identify <filename>.png or *.png returns the information which png files are saved with the problematic profile.

How can I remove the profile so that no warning is displayed?

With the program Gimp, the profile can be changed to a new/better one using the option: Image > Mode > Assign Color Profile.

Modifying the png profile is also possible with the ImageMagicks "mogrify" command.

If the program is started from the command line with mogrify *.png, all png files in the parent working directory are changed.

Info: All png files included in the WinCC OAversion have already been updated to avoid the warnings.

Will there be a loss of quality?

No, if you only remove the color profile, e.g. with the mogrify command, there will be no loss of quality.

If you use a new, more suitable profile for your target hardware, you may even notice an improvement in quality as the colors are more natural.

There are two ways to enable multi touch on Web Client UIs.

First option:

To use the touch or multi touch functionality on Web Client UI the server project config has to contain [ui] usesTouchScreen = 1 as well.

Afterwards the project can be downloaded to the client host by the Web Client functionality.

Second option:

Another option for touch or multi touch functionality can be achieved by an additional parameter within the server side file webclient_index.html:

<param name="arguments" value="-touch">

If there is any unexpected behavior during touch operations, please use the config entry above.